In many industrial processes, real time online measurements of the concentration of the reactants and products of interest may be essential to process control. Various analytical methods including liquid or gas chromatography, mass spectrometry, spectrophotometry, and electrochemical methods have been applied. Electrochemical methods may be convenient because they can be used online and are relatively inexpensive. However most electrochemical analyses are focused on low concentrations of analyte, typically in the mM range, because of various problems like mass transfer contributions from migration and large resistive drops at M-level concentrations.
Ultramicroelectrodes (UMEs) may be a tool in electrochemical measurements in resistive solution, spatial resolution analysis, sensor for in vivo measurements, and electrode kinetics under steady state conditions. However, a need exists to measure high concentration of ions in solutions that contain organics using voltammetric techniques, such as, but not limited to, UMEs.